In the assembling of optical systems, various components are typically assembled. Each component of an assembly must be positioned and aligned. Specific displacements and angles between optical elements along an optical path must typically be aligned as precisely as the requirements of the optical system. Various alignment mechanisms are used to assure alignment of the various components. Each component must be accurately positioned with respect to the intended propagation direction of electromagnetic radiation (e.g., light, at whatever frequency) is intended to travel.
The accuracy to which optical elements are initially positioned influences to a large extent the quality or precision of the system. Potential position errors may be induced in an assembly during assembly, alignment, adjustment, calibration, or operation of the components.
The alignment process itself is meticulous as each joint that is released in order to move a component may miss-align in more than the single degree of freedom desired to be adjusted. Thus, the alignment process is time consuming.
Because optical assemblies are assembled from several separate pieces, at each interface between components certain stresses will be induced by fastening mechanisms and processes. Those stresses may be created during assembly, during alignment, and during operation. For example, optical systems are often used in environments that undergo large temperature excursions. Specifically, cryogenic optics may operate at temperatures well below ambient, sometimes at only a few degrees Kelvin, from about 4 degrees Kelvin to 80 degrees Kelvin, or somewhat more.
Meanwhile, devices must be manufactured and set up by human beings at standard atmospheric temperatures and pressures. At every joint, thermal stresses and unpredictable stick, slip, or both may occur due to residual stresses from fastening, thermal expansion and contraction of components, or both. Changes in temperature during the life of an instrument often cause variations in net expansion or contraction of materials as a result of temperature variations, material property differences, and usually both. Accordingly, over time, and over temperature, various additional stresses may be induced, relieved, or both.
The net effect is changes in position over time caused by the components and the alignment mechanism. Accordingly, these influences all affect the accuracy with which an optic can be aligned so light rays will pass through the optical system as precisely as desired. Accordingly, the accuracy of the optical system is very dependent on the ability to align and maintain in alignment the components of the system.
What is needed is an optic mount that is more easily aligned and less influenced by the foregoing sources of error during alignment and over time.